论文标题
粘弹性介质的粘合剂接触中的尺寸效应
Size effects in adhesive contacts of viscoelastic media
论文作者
论文摘要
从粘弹性基板上脱离刚性球体所需的最大力是否取决于接触半径的初始值？文献中报道的实验和理论研究给出了相反的反应。在这里，我们尝试通过利用完全确定的模型来回答上述问题，在该模型中，Lennard-Jones的潜力和标准线性固体模型的粘弹性描述了粘合剂相互作用。当在准静态条件下进行进近和缩回阶段时，底物作为弹性介质的表现，并且正如预期的那样，发现拉的力FPO（即最大拉伸力）与负载结束时达到的最大接触半径amax无关。相反，当瞬态效应随着接触面积越大时，尺寸依赖性效应（即与Amax的拉力FPO随着AMAX的变化而变化），散发效应越大，耗散涉及的大容量的尺寸就越大。根据粘弹性裂纹的理论，还讨论了结果，该理论被修改以捕获与Amax相关的尺寸效应。
Is the maximum force required to detach a rigid sphere from a viscoelastic substrate dependent on the initial value of the contact radius? Experimental and theoretical investigations reported in the literature have given opposite responses. Here, we try to answer the above question by exploiting a fully deterministic model in which adhesive interactions are described by Lennard-Jones potential and the viscoelastic behaviour with the standard linear solid model. When the approach and retraction phases are performed under quasi-static conditions, the substrate behaves as an elastic medium and, as expected, the pull-off force Fpo (i.e., the maximum tensile force) is found to be independent of the maximum contact radius amax reached at the end of loading. Size-dependent effects are instead observed (i.e., pull-off force Fpo changes with amax) when transient effects occur as the larger the contact area, the greater the size of the bulk volume involved in the dissipation. Results are also discussed in the light of viscoelastic crack Persson's theory, which is modified to capture size effects related to amax.
